Hardware Acceleration

Frame supports hardware-accelerated video encoding using your GPU, providing significantly faster encoding speeds compared to software encoding. This guide covers NVIDIA NVENC and Apple VideoToolbox encoders.

Overview

Hardware encoders use dedicated silicon on your GPU to encode video, offloading work from the CPU.

Benefits

5-10x faster encoding compared to software codecs
Lower CPU usage - frees CPU for other tasks
Real-time encoding possible for high-resolution video
Lower power consumption on laptops

Tradeoffs

Slightly larger files (10-20%) at equivalent quality settings
Less control over encoding parameters
Requires compatible hardware (recent NVIDIA GPU or Apple Silicon)

Hardware encoding is ideal when speed is more important than achieving the absolute smallest file size.

Hardware Decode Acceleration

In addition to hardware encoding, Frame supports hardware decode acceleration via the hwDecode option. Setting: hwDecode: true

How It Works

Decodes the input video using GPU hardware acceleration
Available for both NVENC (CUDA) and VideoToolbox encoders
Further reduces CPU usage during conversion

When to Enable

Encoding high-resolution video (4K, 8K)
Processing multiple files simultaneously
Minimizing CPU load
Laptop/battery-powered usage

Implementation

When hwDecode is enabled, Frame automatically adds the appropriate hardware acceleration flags: For NVENC (NVIDIA):

-hwaccel cuda -hwaccel_output_format cuda

For VideoToolbox (Apple):

-hwaccel videotoolbox

Hardware decode requires the source video codec to be supported by your GPU. Most modern GPUs support H.264/H.265 decode acceleration.

NVIDIA NVENC

NVIDIA’s hardware encoder available on GeForce, Quadro, and Tesla GPUs.

Requirements

NVIDIA GPU with NVENC support (GTX 600 series or newer)
Recent drivers installed
CUDA support enabled

Supported Codecs

H.264 NVENC
H.265 NVENC
AV1 NVENC

h264_nvenc

Hardware-accelerated H.264 encoding using NVIDIA GPU.Codec ID: h264_nvenc

Use Cases

Fast H.264 encoding (5-10x faster than libx264)
Real-time recording and streaming
Batch processing large video libraries
4K video encoding
Screen recording

Quality Control

Frame uses NVIDIA’s VBR (Variable Bitrate) mode with CQ (Constant Quality):Quality Setting: The quality field (0-100) maps to NVENC’s CQ parameter:

Quality 100 → CQ 1 (best quality, largest files)
Quality 50 → CQ 26 (balanced)
Quality 0 → CQ 51 (lowest quality, smallest files)

The formula: CQ = 52 - (quality / 2)

Recommended Quality Settings

Quality 60-70: High quality (CQ 22-17)
Quality 50: Balanced (CQ 26) - Default
Quality 30-40: Lower quality (CQ 32-27)

Example Configuration

{
  "videoCodec": "h264_nvenc",
  "quality": 50,
  "preset": "medium",
  "hwDecode": true
}

NVENC quality “50” produces comparable results to software CRF 23-25, but encodes 5-10x faster.

hevc_nvenc

Hardware-accelerated H.265/HEVC encoding using NVIDIA GPU.Codec ID: hevc_nvenc

Use Cases

Fast 4K/8K encoding
High-efficiency archival (better compression than H.264)
Real-time HEVC streaming
Modern device ecosystems

Quality Control

Same VBR+CQ system as h264_nvenc:

Quality field (0-100) maps to CQ (1-51)
Formula: CQ = 52 - (quality / 2)

Compression Efficiency

20-30% better compression than h264_nvenc
Similar encoding speed to h264_nvenc
Requires NVENC generation 2+ (Maxwell/GTX 900 series or newer)

Example Configuration

{
  "videoCodec": "hevc_nvenc",
  "quality": 55,
  "preset": "slow",
  "hwDecode": true
}

av1_nvenc

Hardware-accelerated AV1 encoding using NVIDIA GPU.Codec ID: av1_nvenc

Requirements

NVIDIA RTX 40 series GPU (Ada Lovelace architecture)
GeForce RTX 4050 or higher
Studio Driver 522.25 or newer

Use Cases

Fast AV1 encoding (100x+ faster than software AV1)
Streaming platforms adopting AV1 (YouTube, Twitch)
Maximum compression with reasonable speed
Future-proof encoding

Quality Control

Same VBR+CQ system as other NVENC codecs:

Quality field (0-100) maps to CQ (1-51)
Formula: CQ = 52 - (quality / 2)

Compression vs Software AV1

Comparable quality to software AV1 (libaom-av1)
100-200x faster encoding
30-40% better compression than hevc_nvenc

AV1 NVENC requires RTX 40 series GPUs. It will not work on RTX 30 series or older cards.

Example Configuration

{
  "videoCodec": "av1_nvenc",
  "quality": 50,
  "preset": "p4",
  "hwDecode": true
}

NVENC Presets

NVENC uses different preset names than software encoders. Frame automatically maps software presets to NVENC equivalents: Native NVENC Presets:

p1 - Fastest (lowest quality)
p2
p3
p4 - Balanced
p5
p6
p7 - Slowest (best quality)

Software Preset Mapping: When using standard software preset names, Frame maps them:

ultrafast, superfast, veryfast, faster → fast
fast → fast
medium → medium (default)
slow → slow
slower, veryslow → slow

You can use either NVENC native presets (p1-p7) or standard preset names (fast/medium/slow) in Frame.

NVENC Advanced Options

Frame exposes two NVENC-specific quality enhancement options:

Spatial AQ
Temporal AQ

Spatial Adaptive Quantization

Setting: nvencSpatialAq: true

What It Does

Allocates more bits to complex/detailed areas of the frame and fewer bits to flat areas.

Benefits

Improved perceived quality
Better detail preservation in complex scenes
More efficient bit allocation

When to Use

Content with varying complexity (movies, nature footage)
When quality is important
Minimal speed impact (~5% slower)

Implementation

-spatial_aq 1

Spatial AQ is recommended for most use cases. It provides better quality with minimal performance impact.

Temporal Adaptive Quantization

Setting: nvencTemporalAq: true

What It Does

Analyzes motion across frames to allocate bits more efficiently over time.

Benefits

Better quality in motion sequences
Reduced temporal artifacts
Improved quality in action scenes

When to Use

High-motion content (sports, action movies)
When encoding speed is not critical (~10% slower)
Used together with Spatial AQ for best results

Implementation

-temporal_aq 1

Combined Usage

{
  "videoCodec": "h264_nvenc",
  "nvencSpatialAq": true,
  "nvencTemporalAq": true,
  "quality": 55
}

Apple VideoToolbox

Apple’s hardware encoder for macOS and iOS devices, integrated into Apple Silicon and Intel Macs with T2 chips.

Requirements

Apple Silicon (M1, M2, M3, M4 series) - Recommended
Intel Mac with T2 chip (limited support)
macOS 10.13 or newer

Supported Codecs

H.264 VideoToolbox
H.265 VideoToolbox

h264_videotoolbox

Hardware-accelerated H.264 encoding using Apple’s VideoToolbox framework.Codec ID: h264_videotoolbox

Use Cases

Fast encoding on Apple Silicon Macs
Native macOS/iOS video encoding
Real-time recording on Mac
Batch processing on M-series chips
Low power consumption encoding on laptops

Quality Control

VideoToolbox uses a different quality system than software encoders:Quality Setting: The quality field (0-100) directly maps to VideoToolbox’s quality parameter:

Quality 0-100 (higher is better)
Quality 50 is the default (balanced)
Quality 60-80 for high quality

Unlike CRF (lower is better), VideoToolbox quality is higher = better.

Presets

VideoToolbox does not use presets - it has its own optimized encoding path.

Example Configuration

{
  "videoCodec": "h264_videotoolbox",
  "quality": 50,
  "hwDecode": true
}

On Apple Silicon, VideoToolbox encoding is extremely efficient and fast, especially for 4K video.

hevc_videotoolbox

Hardware-accelerated H.265/HEVC encoding using Apple VideoToolbox.Codec ID: hevc_videotoolbox

Use Cases

4K/8K encoding on Apple Silicon
High-efficiency archival on Mac
HEVC for Apple ecosystem delivery
ProRes to HEVC conversion

Quality Control

Same quality system as h264_videotoolbox:

Quality 0-100 (higher = better)
Quality 55-65 recommended for high quality

Performance

20-30% better compression than h264_videotoolbox
Similar encoding speed on Apple Silicon
Excellent power efficiency

Example Configuration

{
  "videoCodec": "hevc_videotoolbox",
  "quality": 60,
  "hwDecode": true
}

VideoToolbox Advanced Options

Allow Software Fallback

videotoolboxAllowSw

Setting: videotoolboxAllowSw: true

What It Does

Allows VideoToolbox to fall back to software encoding if hardware encoding fails or is unavailable.

When to Use

Ensuring encoding always succeeds
Compatibility with older/unsupported configurations
Testing on systems with limited hardware support

Implementation

-allow_sw 1

Example Configuration

{
  "videoCodec": "h264_videotoolbox",
  "quality": 50,
  "videotoolboxAllowSw": true
}

When software fallback is triggered, encoding speed will be significantly slower (similar to libx264).

Hardware vs Software Encoding

When to Use Hardware Encoding

Speed is Priority

Use hardware encoding when:

Processing large video libraries
Real-time encoding or streaming
Quick turnaround needed
Batch processing many files
4K/8K video encoding
Laptop/battery usage (lower power consumption)

Recommended:

NVIDIA: h264_nvenc or hevc_nvenc
Apple: h264_videotoolbox or hevc_videotoolbox

Quality/Size is Priority

Use software encoding when:

Archival quality is paramount
Minimizing file size is critical
Encoding time is not a concern
Maximum compression efficiency needed
Advanced encoding controls required

Recommended:

libx264 (H.264) with slow/slower preset
libx265 (H.265) with slow preset

Quality Comparison

At equivalent quality settings, file size differences:

Encoder	Relative File Size	Encoding Speed
libx264 (veryslow)	1.0x (baseline)	1x
libx264 (medium)	1.1x	4x
h264_nvenc (slow)	1.2x	10x
h264_videotoolbox	1.15x	8x
libx265 (slow)	0.6x	0.3x
hevc_nvenc (slow)	0.75x	8x
hevc_videotoolbox	0.7x	6x

Hardware encoders produce 10-20% larger files but encode 5-10x faster. Choose based on your priorities.

Performance Tips

Maximum Speed
Balanced Quality/Speed
Best Hardware Quality

Optimizing for Speed

For fastest possible encoding:

{
  "videoCodec": "h264_nvenc",
  "preset": "fast",
  "quality": 50,
  "hwDecode": true,
  "nvencSpatialAq": false,
  "nvencTemporalAq": false
}

Expected Speed:

4K video: 100-200+ FPS on modern GPUs
1080p video: 300-500+ FPS
Real-time encoding for up to 8K

Balanced Configuration

For good quality with fast encoding:NVIDIA:

{
  "videoCodec": "hevc_nvenc",
  "preset": "medium",
  "quality": 55,
  "hwDecode": true,
  "nvencSpatialAq": true,
  "nvencTemporalAq": false
}

Apple:

{
  "videoCodec": "hevc_videotoolbox",
  "quality": 60,
  "hwDecode": true
}

Maximum Hardware Quality

For best quality from hardware encoders:NVIDIA:

{
  "videoCodec": "hevc_nvenc",
  "preset": "p7",
  "quality": 65,
  "hwDecode": true,
  "nvencSpatialAq": true,
  "nvencTemporalAq": true
}

Apple:

{
  "videoCodec": "hevc_videotoolbox",
  "quality": 70,
  "hwDecode": true
}

Troubleshooting

Hardware Encoder Not Available

Error: Encoder not found

NVIDIA

Update GPU drivers to latest version
Verify GPU supports NVENC (GTX 600+)
Check that CUDA is installed
For AV1: Requires RTX 40 series

Apple

Requires macOS 10.13+
Verify Apple Silicon or T2 chip
Update macOS to latest version

Hardware Decode Fails

Error: Hardware decode acceleration failed

Source video codec may not support hardware decode
Try disabling hwDecode option
Check GPU driver version
Verify sufficient VRAM available

Quality Lower Than Expected

Output quality is poor

Increase quality setting (50 → 60 → 70)
For NVENC: Enable Spatial AQ and Temporal AQ
Use slower preset (medium → slow → p7)
Consider software encoding for archival quality

Get Started

Features

Guides

Development

​Hardware Acceleration

​Overview

​Benefits

​Tradeoffs

​Hardware Decode Acceleration

​How It Works

​When to Enable

​Implementation

​NVIDIA NVENC

​Requirements

​Supported Codecs

​h264_nvenc

​Use Cases

​Quality Control

​Recommended Quality Settings

​Example Configuration

​hevc_nvenc

​Use Cases

​Quality Control

​Compression Efficiency

​Example Configuration

​av1_nvenc

​Requirements

​Use Cases

​Quality Control

​Compression vs Software AV1

​Example Configuration

​NVENC Presets

​NVENC Advanced Options

​Spatial Adaptive Quantization

​What It Does

​Benefits

​When to Use

​Implementation

​Temporal Adaptive Quantization

​What It Does

​Benefits

​When to Use

​Implementation

​Combined Usage

​Apple VideoToolbox

​Requirements

​Supported Codecs

​h264_videotoolbox

​Use Cases

​Quality Control

​Presets

​Example Configuration

​hevc_videotoolbox

​Use Cases

​Quality Control

​Performance

​Example Configuration

​VideoToolbox Advanced Options

​videotoolboxAllowSw

​What It Does

​When to Use

​Implementation

​Example Configuration

​Hardware vs Software Encoding

​When to Use Hardware Encoding

​Quality Comparison

​Performance Tips

​Optimizing for Speed

​Balanced Configuration

​Maximum Hardware Quality

​Troubleshooting

​Error: Encoder not found

​NVIDIA

​Apple

​Error: Hardware decode acceleration failed

​Output quality is poor

​See Also

Build docs developers (and LLMs) love

Hardware Acceleration

Overview

Benefits

Tradeoffs

Hardware Decode Acceleration

How It Works

When to Enable

Implementation

NVIDIA NVENC

Requirements

Supported Codecs

h264_nvenc

Use Cases

Quality Control

Recommended Quality Settings

Example Configuration

hevc_nvenc

Use Cases

Quality Control

Compression Efficiency

Example Configuration

av1_nvenc

Requirements

Use Cases

Quality Control

Compression vs Software AV1

Example Configuration

NVENC Presets

NVENC Advanced Options

Spatial Adaptive Quantization

What It Does

Benefits

When to Use

Implementation

Temporal Adaptive Quantization

What It Does

Benefits

When to Use

Implementation

Combined Usage

Apple VideoToolbox

Requirements

Supported Codecs

h264_videotoolbox

Use Cases

Quality Control

Presets

Example Configuration

hevc_videotoolbox

Use Cases

Quality Control

Performance

Example Configuration

VideoToolbox Advanced Options

videotoolboxAllowSw

What It Does

When to Use

Implementation

Example Configuration

Hardware vs Software Encoding

When to Use Hardware Encoding

Quality Comparison

Performance Tips

Optimizing for Speed

Balanced Configuration

Maximum Hardware Quality

Troubleshooting

Error: Encoder not found

NVIDIA

Apple

Error: Hardware decode acceleration failed

Output quality is poor

See Also